Symptoms and Treatment of Grape and Raisin Poisoning

ImmunityDiseasesMeongsiljang Veterinary Advisory Board

We’ll guide you through the signs of poisoning, emergency first aid, and veterinary treatment for pets that have eaten grapes or raisins.

What Is Grape and Raisin Poisoning?

A worried pet owner holding their dog at the veterinary clinic reception desk

Grape and raisin poisoning is a dietary toxicity that can cause acute kidney injury in pets that have ingested grapes or raisins. The key point is that individual responses can vary significantly. More than half of exposed dogs show no symptoms at all, yet some individuals can develop severe kidney damage even after consuming very small amounts. Because it is impossible to predict which dogs will be sensitive, no amount can be considered safe. If treatment is delayed, kidney failure can become life-threatening. Currently, veterinary literature reports grape and raisin poisoning primarily in dogs. If you discover your dog has eaten grapes or raisins, seek immediate veterinary care even if no symptoms are present.

Why Are Grapes Dangerous?

While the exact cause of grape and raisin toxicity has long been a mystery, recent veterinary toxicology research points to tartaric acid as the likely culprit. Because tartaric acid levels vary depending on the grape variety and ripeness, the severity of poisoning can differ even when the same amount is consumed. Raisins (dried grapes) are assessed for toxicity using the same standards as fresh grapes. Although some reports suggest that heated foods containing raisins, such as breads and cookies, may pose a lower risk of acute kidney injury (AKI) because heat partially breaks down tartaric acid, it is still not safe to assume they are harmless. One important point is that commercially available grape juice, grape wine, and grape jam (jelly) undergo detartration, a process that removes tartaric acid, and are reported to carry no risk of kidney failure. However, whole grapes and raisins themselves remain dangerous, so caution is still required with any foods that contain them.

Checklist of Major Symptoms of Grape Poisoning

Vomiting is typically the first sign of grape toxicity, usually appearing within six hours of ingestion. Blood kidney values (BUN and creatinine) begin to rise 12 to 18 hours after consumption. If you notice any of the following symptoms, suspect poisoning:

Vomiting: This is often the earliest symptom, and vomit may contain pieces of the ingested grapes.

Diarrhea: This frequently occurs alongside vomiting.

Lethargy and Loss of Appetite: Your pet may appear unusually weak or listless and refuse to eat.

Abdominal Pain: Your pet may show signs of pain when their abdomen is touched or may curl up.

Changes in Urination: In the early stages of kidney damage, urination may actually increase (polyuria). As the condition progresses, urination may decrease (oliguria) or stop completely (anuria).

Dehydration: Signs include dry gums and reduced skin elasticity.

A sick puppy lying listlessly on a blanket

Go to the Vet Immediately If You See These Symptoms

If you’ve confirmed your pet ate grapes or raisins, or if they’re showing vomiting, decreased urination, or lethargy, head to an emergency veterinary clinic immediately. In particular, if your pet hasn’t urinated for more than 12 hours, vomiting persists, or their consciousness becomes clouded, kidney failure may already be progressing. Write down the time of ingestion and the estimated amount consumed, and share this information with the veterinarian.

Diagnostic Process at the Veterinary Clinic

The veterinarian will first review your pet’s grape ingestion history and current symptoms, then proceed with blood and urine tests.

Blood test: Checks creatinine and blood urea nitrogen (BUN) levels, which are indicators of kidney function. Elevated levels suggest that kidney damage has begun.

Urine test: Assesses the kidneys’ ability to concentrate urine and checks for protein leakage.

Electrolyte and metabolic panel: Abnormal phosphorus or calcium levels, or metabolic acidosis, can signal the progression of kidney failure.

Even if initial blood test results appear normal, follow-up tests should be conducted at 24-hour and 48-hour intervals after the initial measurement, as kidney damage may manifest later.

Treatment Methods

Treatment is divided into two main steps: decontamination and fluid therapy.

Decontamination: The veterinarian will induce vomiting to remove the grapes from the stomach, taking into account the amount ingested and the time since ingestion. Inducing vomiting is recommended if the dog has consumed more than one grape per 10 pounds (approximately 5 kg) of body weight. Afterward, activated charcoal is administered to reduce the absorption of any remaining toxins.

Fluid Therapy: Intravenous fluids are provided to increase blood flow to the kidneys and help flush out toxins. Kidney values (BUN and creatinine) are monitored at 24-hour and 48-hour intervals after initial baseline measurements, and continued tracking is performed if kidney damage is detected. Urine output is also closely monitored throughout the process.

Supportive Care: If vomiting is severe, antiemetics are administered, and electrolyte imbalances are corrected as needed.

A veterinarian administering intravenous fluid therapy to a dog at an animal hospital

Post-Discharge Home Care Points

Even after discharge, follow your veterinarian’s schedule for rechecks to confirm that kidney function has fully recovered.

Hydration: Place fresh, clean water in several locations around your home to encourage adequate drinking.

Dietary management: If acute kidney injury has occurred, your veterinarian may recommend a prescription renal diet. These diets are formulated with controlled levels of protein and phosphorus to reduce the workload on the kidneys.

Urination monitoring: Check your pet’s urine output and color daily. Contact your clinic immediately if you notice decreased urine volume or darker urine.

Rechecks: Kidney values (BUN and creatinine) are typically monitored with follow-up tests at 24-hour and 48-hour intervals after the initial baseline measurement. If kidney damage was present, be sure to complete any additional tests recommended by your veterinarian on the specified schedule.

A puppy recovering comfortably at home with a water bowl

Essential Rules for Preventing Grape Poisoning

Prevention is the best approach for grape and raisin toxicity. Keep grapes, raisins, and any bread, snacks, or salads containing raisins completely out of reach of your pets. Although commercially available grape juice, wine, and jam are reported to pose no risk of kidney failure because tartaric acid has been removed, they may contain other problematic ingredients such as sugars, so it’s best not to give them to pets. Make sure everyone in your household, especially children, understands that grapes should never be given to pets. Be vigilant during walks to prevent your pet from eating dropped grapes, and place fruit bowls out of reach when guests visit.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Should I take my pet to the vet even if it only ate one grape?

Yes, you must take your dog to the vet. Grapes and raisins can cause acute kidney injury in dogs, and reactions vary widely among individuals. While more than half of exposed dogs show no symptoms, some dogs can develop severe kidney damage from even a small amount. Since it's impossible to predict which dogs are sensitive, if your dog has eaten even one grape or raisin, seek veterinary care immediately.

Can cats get grape poisoning too?

Current veterinary textbooks primarily report grape and raisin toxicity in dogs. There is not yet sufficient textbook-level evidence directly supporting toxicity in cats. Nevertheless, as a precautionary measure, it is safest to prevent cats from accessing grapes and raisins.

It’s been a while since my pet ate grapes, but there are no symptoms. Is that okay?

Even if there are no symptoms, don’t let your guard down. Kidney markers (BUN and creatinine) may start to rise 12 to 18 hours after ingestion. It’s essential to have blood tests done at a veterinary clinic to check kidney function.

Is it safe to induce vomiting at home?

Inducing vomiting on your own can be dangerous. If done incorrectly, it can lead to secondary complications such as aspiration pneumonia. It is essential to have a veterinarian assess and safely manage the situation.

Can a pet fully recover after grape poisoning?

With early and appropriate decontamination and fluid therapy, most pets can make a full recovery. However, if the condition has progressed to oliguria or anuria, the prognosis is poor. Delayed treatment that leads to severe renal failure can result in permanent kidney damage. Prompt intervention is crucial in determining the outcome.

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References

[1] Eubig PA, Brady MS, Gwaltney-Brant SM et al., Acute renal failure in dogs after the ingestion of grapes or raisins: a retrospective evaluation of 43 dogs (1992–2002), Journal of Veterinary Internal Medicine, 2005

[2] Wegenast C, Meadows I, Possible tartaric acid etiology for grape and raisin toxicosis in dogs, ASPCA Animal Poison Control Center, 2021

[3] Blackwell's Five-Minute Veterinary Consult Clinical Companion, Small Animal Toxicology, 3rd Edition

[4] Clinical Medicine of the Dog and Cat, 4th Edition

[5] Plumb's Veterinary Drug Handbook, 10th Edition

[6] Feline Emergency and Critical Care Medicine, 2nd Edition